engine wont even really rev in neutral past about 3300 or so...

tends to knock with higher loads... almost any acceleration in 6th and it knocks, or maintaining up a hill... when it knocks, seems to add about 300-400 to the knock counter. and depending on the throttle position they start coming really fast and faint(floored), or slow and strong(medium accelerator, enough to keep spark advance without it knocking). either way though, the engine retards and i usually downshift to get more power.

Replaced in last 6 months to remove problem:

Fuel Pressure Regulator
Fuel Pump
Ignition Coil
ICM
OPTI
spark plugs, wires

not sure what else... idle is acceptable, probably could be a little smoother, but I wouldnt say its running rough at all.

dont know where to go from here...

doesnt throw any codes.

 

Have you checked it for a plugged cat? Anything loose in the engine or exhaust that could be causing false knock?

 

Do a compression test. Just went through this same thing with a guy on the truck forum. Blown head gasket.

 

I'm pretty sure its not a false knock because my clutch really kicks back at me, exactly the same time my knock sensor changes. and i can drive it softly around town without getting the knock counter to change, so its fairly predictable...

i have thought about the plugged cat... i have to pull them off, i got the kooks exhaust with 2 high flow SLP cats(less than 1 year old), so i could pull it off and take a look.

 

on the note of a clogged cat... something...

pulled off my y-pipe and exhaust pipes... so far... my drive side cat is completely gutted... guessing the shrapnel is in the muffler somewhere... haven't taken off the muffler yet... taking a small break.

the passenger side cat seems like someone pushed on it in the center... and its spiraling toward the catback... but all is still there.

dont know if this is the problem or if this is another symptom of the problem...

hopefully my muffler is just clugged up and thats the end of it.

but on a second note what could cause the SLP cat to be destroyed?

 

wow... muffler full of trash... i guess i get the passenger side cat gutted before i have to do all this again... no sense in having uneven pressure on both sides...

 

I had a similar problem... Aftermarket cat busted up and ended up in the muffler clogging it. It would barely run, no power. Running rich can send unburned fuel into the exhaust causing them to melt down, but I think my problem was hitting too many speed bumps with the cat hanging low off the Y pipe .

 

yea, my car certainly hasnt been this loud in a long time... scary though... cause i got inspection coming up soon... and the germans are strict about this... i guess i'll figure a way out...

i spent a lot of headaches over this problem... now i got to figure out how to make it quieter... thinking of a bullet muffler in addition to my magnaflow

 

I chased false knock for a few months. Ended up being an over torqued knock sensor.

 

Good that you caught that, the factory manual is very specific about getting that thing torqued to the correct setting.

 

good to know, mine isn't on all the way... my crescent wrench stopped fitting, so i gave up, but i broke down and bought a whole set of craftsman open/boxed wrenches, so i should probably go finish the job.

i still have a small knock, not as bad, perhaps my oxygen sensors are done, since the inside of the exhaust piping was covered in black soot.